<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script type="text/javascript" src="../script/jquery-1.7.2.js"></script>
    <script type="text/javascript">
        $(function () {

            // $(":radio").val(["radio1"]); //设置value=radio1的单选框被选中
            // $(":checkbox").val(["checkbox1", "checkbox3"]);//批量操作复选框的选中状态
            // $("#multiple").val(["mul1", "mul3", "mul4"]);//批量操作下拉框多选的选中状态
            // $("#single").val("sin2");//操作下拉框单选的选中状态

            $(":radio, :checkbox, #multiple").val(["radio2", "checkbox1", "mul1"]);
        })
    </script>
</head>
<body>
    单选：
    <input name="radio" type="radio" value="radio1" />radio1
    <input name="radio" type="radio" value="radio2" />radio2 <br/>

    多选：
    <input name="checkbox" type="checkbox" value="checkbox1" />checkbox1
    <input name="checkbox" type="checkbox" value="checkbox2" />checkbox2
    <input name="checkbox" type="checkbox" value="checkbox3" />checkbox3 <br/>

    下拉多选：
    <select id="multiple" multiple="multiple" size="4">
        <option value="mul1">mul1</option>
        <option value="mul2">mul2</option>
        <option value="mul3">mul3</option>
        <option value="mul4">mul4</option>
    </select> <br/>

    下拉单选 ：
    <select id="single">
        <option value="sin1">sin1</option>
        <option value="sin2">sin2</option>
        <option value="sin3">sin3</option>
    </select>
</body>
</html>